Misc

Signed-off-by: Mattias Andrée <m@maandree.se>

1 files changed, 140 insertions, 0 deletions

diff --git a/libtest/random.c b/libtest/random.c
new file mode 100644
index 0000000..77e9218
--- /dev/null
+++ b/libtest/random.c
@@ -0,0 +1,140 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+
+unsigned char *libtest_random_pattern = NULL;
+size_t libtest_random_pattern_length = 0u;
+size_t libtest_random_pattern_offset = 0u;
+
+static ssize_t
+genpattern(void *buf, size_t size)
+{
+	unsigned char *out = buf;
+	size_t n;
+
+	if (size > (size_t)SSIZE_MAX)
+		size = (size_t)SSIZE_MAX;
+
+	if (libtest_random_pattern_length) {
+		while (size) {
+			if (libtest_random_pattern_offset == libtest_random_pattern_length)
+				libtest_random_pattern_offset = 0u;
+			n = libtest_random_pattern_length - libtest_random_pattern_offset;
+			if (n > size)
+				n = size;
+			memcpy(out, &libtest_random_pattern[libtest_random_pattern_offset], n);
+			out = &out[n];
+			size -= n;
+			libtest_random_pattern_offset += n;
+		}
+	} else {
+		for (; size; size--, out++)
+			out[0] = (unsigned char)rand();
+	}
+
+	return (ssize_t)size;
+}
+
+
+#if defined(__linux__)
+int libtest_getrandom_real = 1;
+int libtest_getrandom_error = 0;
+size_t libtest_getrandom_max_return = SIZE_MAX;
+
+ssize_t
+(getrandom)(void *buf, size_t size, unsigned int flags)
+{
+	if (size > libtest_getrandom_max_return)
+		size = libtest_getrandom_max_return;
+
+	if (libtest_getrandom_error) {
+		errno = libtest_getrandom_error;
+		if (libtest_getrandom_error == EINTR)
+			libtest_getrandom_error = 0;
+		return -1;
+	}
+
+	if (!libtest_getrandom_real)
+		return genpattern(buf, size);
+
+# if defined(SYS_getrandom)
+	return syscall(SYS_getrandom, buf, size, flags);
+# else
+	errno = ENOSYS;
+	return -1;
+# endif
+}
+#endif
+
+
+int libtest_getentropy_real = 1;
+int libtest_getentropy_error = 0;
+size_t libtest_getentropy_calls = 0u;
+int libtest_getentropy_jmp_val = 0;
+jmp_buf libtest_getentropy_jmp;
+
+int
+(getentropy)(void *buf, size_t size)
+{
+	unsigned char *out = buf;
+	ssize_t r;
+
+	libtest_getentropy_calls += 1u;
+
+	if (libtest_getentropy_jmp_val)
+		longjmp(libtest_getentropy_jmp, libtest_getentropy_jmp_val);
+
+	if (libtest_getentropy_error) {
+		errno = libtest_getentropy_error;
+		if (libtest_getentropy_error == EINTR)
+			libtest_getentropy_error = 0;
+		return -1;
+	}
+
+	if (size > 256u) {
+		errno = EIO;
+		return -1;
+	}
+
+	if (!libtest_getentropy_real) {
+		r = genpattern(out, size);
+		if (r == (ssize_t)size)
+			return 0;
+		errno = EIO;
+		return -1;
+	}
+
+#if defined(__linux__) && defined(SYS_getrandom)
+	while (size) {
+		r = (ssize_t)syscall(SYS_getrandom, out, size, 0);
+		if (r < 0) {
+			if (errno == EINTR)
+				continue;
+			if (errno != ENOSYS)
+				errno = EIO;
+			return -1;
+		}
+		out = &out[r];
+		size -= (size_t)r;
+	}
+	return 0;
+#else
+	errno = ENOSYS;
+	return -1;
+#endif
+}
+
+
+#else
+
+
+CONST int
+main(void)
+{
+	/* TODO maybe test */
+	return 0;
+}
+
+
+#endif